[cridal]

What do you guys think about a system that would 'guide' the user through the process of creating a star schema data warehouse (Kimball style)?

The advantage of this approach would be the fact that you do the dirty laundry upfront during the modeling & population phases. The end result is a data structure that is fool-proof, i.e. there is only one way to join facts/dimensions, it's self-documenting. In fact pre-joined views could automatically be created (and persisted if need be), giving the business user a clean structure to interact with.